pip install -vvv pyvenv
Collecting pyvenv
  1 location(s) to search for versions of pyvenv:
  * https://pypi.python.org/simple/pyvenv/
  Getting page https://pypi.python.org/simple/pyvenv/
  Looking up "https://pypi.python.org/simple/pyvenv/" in the cache
  No cache entry available
  Starting new HTTPS connection (1): pypi.python.org
  "GET /simple/pyvenv/ HTTP/1.1" 404 28063
  Status code 404 not in [200, 203, 300, 301]
  Could not fetch URL https://pypi.python.org/simple/pyvenv/: 404 Client Error: Not Found for url: https://pypi.python.org/simple/pyvenv/ - skipping
  Could not find a version that satisfies the requirement pyvenv (from versions: )
Cleaning up...
No matching distribution found for pyvenv
Exception information:
Traceback (most recent call last):
  File "/usr/local/lib/python2.7/site-packages/pip/basecommand.py", line 209, in main
    status = self.run(options, args)
  File "/usr/local/lib/python2.7/site-packages/pip/commands/install.py", line 310, in run
    wb.build(autobuilding=True)
  File "/usr/local/lib/python2.7/site-packages/pip/wheel.py", line 748, in build
    self.requirement_set.prepare_files(self.finder)
  File "/usr/local/lib/python2.7/site-packages/pip/req/req_set.py", line 360, in prepare_files
    ignore_dependencies=self.ignore_dependencies))
  File "/usr/local/lib/python2.7/site-packages/pip/req/req_set.py", line 512, in _prepare_file
    finder, self.upgrade, require_hashes)
  File "/usr/local/lib/python2.7/site-packages/pip/req/req_install.py", line 273, in populate_link
    self.link = finder.find_requirement(self, upgrade)
  File "/usr/local/lib/python2.7/site-packages/pip/index.py", line 489, in find_requirement
    'No matching distribution found for %s' % req
DistributionNotFound: No matching distribution found for pyvenv